I'm working on a motor controller using PWM. I use Arduino Mega and L293d H-Bridge as the motor driver. My Dc motors can be supplied with 6-9 v (they all are equipped with gear box). The problem appears whe I try to stall it or only working it in free rotation, it happens that the L239d H bridge has a voltage drop, for example:
I start suplying it at 6v with High and low signal for make it rotate free but I measure voltage at out pins on L293 and it shows 3.4 v (@ 0.76 A), I think it's a high voltage drop for it.
Is it normal? Anybody can explain why? Do you have any suggestion on how to fix it?